Extremely rapid, robotic method of identifying the nucleotide sequence of a region of DNA. Gel electrophoresis and laser detection of fluorescent tracers are part of method.

cDNA

DNA synthesized from an mRNA transcript through the use of the enzyme reverse transcriptase.

cloning vector

Any DNA molecule that can accept foreign DNA and that can be replicated inside a host cell.

DNA chips

Microarray of thousands of gene sequences that represents a large subset of a genome; stamped onto a glass plate and used to study gene expression.

DNA clone

Fragment of DNA inserted into a vector such as a plasmid and introduced into a host organism; used to make many copies of a particular segment of DNA.

DNA fingerprint

A way to distinguish one individual from all others based on unique differences in parts of their DNA; fragments cut from an individual�s DNA (RFLPs) have a unique pattern of sizes.

DNA ligase

Type of enzyme that catalyzes the sealing of short stretches of DNA into a continuous strand during replication; also seals strand breaks.

gel electrophoresis

Method of separating DNA molecules according to length, or protein molecules according to size and charge. The molecules move apart while migrating through a gel matrix in response to a weak electric current.

gene library

Collection of host cells that contain different cloned DNA fragments representing all or most of a genome.

genetic engineering

Manipulation of an organism�s DNA, usually to alter at least one aspect of phenotype.

genome

All DNA in a haploid number of chromosomes for a species.

genomics

The study of genes and gene function in humans and other organisms.

human gene therapy

The transfer of one or more normal or modified genes into a person to correct a genetic defect, or to boost resistance to a disease.

nucleic acid hybridization

Any basepairing between DNA or RNA strands from different sources.

PCR

Polymerase chain reaction. A method to rapidly copy DNA fragments.

plasmids

A small, circular bacterial DNA molecule having a few genes; replicated independently of the bacterial chromosome.

primer

Short nucleotide sequence that researchers design as an initiation site for synthesis of a DNA strand on a DNA or RNA template.

probe

Short nucleotide sequence that has been labeled with a tracer; designed to hybridize with part of a gene or mRNA.

recombinant DNA technology

Techniques by which DNA molecules from different species can be cut into fragments, spliced together into cloning vectors, and then amplified to useful quantities.

restriction enzymes

One of hundreds of proteins that recognize and cut specific base sequences in double-stranded DNA.

reverse transcriptase

A viral enzyme that catalyzes the assembly of free nucleotides into a strand of DNA on an RNA template.

seed banks

A storage facility where genes of diverse plant lineages are preserved.

tandem repeats

One of many copies of short base sequences positioned one after another on a chromosome; used in DNA fingerprinting.